The present invention relates to a temperature sensor and a heat treating apparatus in which a method for fixing a temperature detecting element to be attached to an inside of a protective tube has been improved.
In a conventional temperature sensor, a thermocouple as a temperature detecting element is fixed to a heat receiving body, is attached to an inside of a protective tube, and is fixed at a predetermined position as in Patent Document 1 (Japanese Patent Laid-Open No. 2002-296122) and Patent Document 2 (Japanese Patent Laid-Open No. 2001-208616), for example. The heat receiving body itself is not attached to a set position in the protective tube accurately but is attached to an inside of the protective tube together with the thermocouple.
However, in the aforementioned conventional temperature sensor, detection accuracy is improved by providing the heat receiving body, but since the heat receiving body itself is not provided at an accurate position or in an accurate direction, there is a problem in a rising characteristic of a temperature in a case where the temperature is measured with high accuracy.
Thus, when a semiconductor wafer is subjected to a heat treatment by controlling the temperature with high accuracy, a slight difference occurs between a detected temperature by the temperature sensor and an actual temperature of the semiconductor wafer, which causes a problem of not being able to perform a desired heat treatment quickly.
Also, in order to reduce the difference between the temperature characteristic of the heated object and the temperature characteristic of the temperature sensor, the heat receiving body needs to have a certain size. When the size of the heat receiving body increases, its own weight inevitably increases as well. Thus, due to an influence of the heat receiving body's own weight, it becomes difficult to arrange the heat receiving body and the thermocouple with high accuracy. Also, due to the heat receiving body's own weight, an attachment portion between the heat receiving body and the thermocouple receives a load, which may cause a problem of breakage or the like.
Also, a multipoint temperature sensor has a plurality of small diameter branch tubes branched from a large diameter main tube. Since thermocouples are provided at tip end portions of the plurality of branch tubes, there is a problem in which it is not easy to fix the thermocouples at accurate positions reliably.
The present invention has been made in consideration of the above respects, and an object of the present invention is to provide a temperature sensor and a heat treating apparatus enabling to fix a temperature detecting element reliably at an accurate position, improving a rising characteristic of a temperature, and enabling high-accuracy temperature control.